Now you can play Gameboy Color games in your browser with this open source emulator.  https://github.com/grantgalitz/GameBoy-Online
For the sake of ease, I've hosted a copy of the emulator here on Darkshade.  http://darkshade.homeip.net/games/gameboy/
You can download a pack of 400+ free legal gameboy roms from here:http://dl.qj.net/psp/homebrew-packs-roms/472-legal-gameboy/gameboy-color-roms.html or more Public Domain ROMs here: http://pdroms.de/files/gameboy/